On Tuesday 02 February 2010 09:57:08 Kurt Kiefer wrote: > Hi all, > > This is a vague/general question. For some background: I have a reason > (control of IA32_PERF_GLOBAL_CTRL) for loading/saving MSRs on VM-entry/ > exit. To get this to work correctly, I made changes to use the > conventional VMX MSR load areas of the VMCS for this particular MSR. > Works great. > > Is there a particular reason why MSRs are currently loaded/saved > through KVM's unconventional facilities (vmx.c:save_msrs(), > vmx.c:load_msrs()), rather than through VM entry/exit MSR load regions > in the VMCS? I see that only long mode guests on x86_64 are effected > by this. > > Any insight could be useful. Do you think MSR loading via VMCS would > be faster? Are there downsides to doing it one way or the other? > Because not all MSRs are supported for automatically save/load when VMX transition happened. You used IA32_PERF_GLOBAL_CTRL is supported. But not the ones saved in save_msrs(). -- regards Yang, Sheng -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
